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Membranes have been used extensively for the purification and separation of biological species. A persistent challenge is the purification of species from concentrated feed solutions such as extracellular vesicles (EVs) from biological fluids. Investigated is a new method to isolate micro‐ and nanoscale species termed tangential flow for analyte capture (TFAC), which is an extension of traditional tangential flow filtration. Initially, EV purification from plasma on ultrathin nanomembranes is compared between both normal flow filtration (NFF) and TFAC. NFF results in rapid formation of a protein cake which completely obscures any captured EVs and also prevents further transport across the membrane. On the other hand, TFAC shows capture of CD63 positive small EVs with minimal contamination. The use of TFAC to capture target species over membrane pores, wash, and then release in a physical process that does not rely upon affinity or chemical interactions is explored. This process is studied with model particles on both ultrathin and conventional thickness membranes. Successful capture and release of model particles is observed using both membranes. Ultrathin nanomembranes show higher efficiency of capture and release with significantly lower pressures indicating that ultrathin nanomembranes are well‐suited for TFAC of delicate nanoscale particles such as EVs.

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Desulfovibrio alaskensis G20 biofilms were cultivated on 316 steel, 1018 steel, or borosilicate 37 glass under steady-state conditions in electron-acceptor limiting (EAL) and electron-donor 38 limiting (EDL) conditions with lactate and sulfate in a defined medium. Increased corrosion was observed on steel under EDLconditions compared to 316 steel, and biofilms on 1018 carbon 40 steel under the EDL condition had at least 2-fold higher corrosion rates compared to the EAL 41 condition. Protecting the 1018 metal coupon from biofilm colonization significantly reduced 42 corrosion, suggesting that the corrosion mechanism was enhanced through attachment between the 43 material and the biofilm. Metabolomic mass spectrometry analyses demonstrated an increase in a 44 flavin-like molecule under the 1018 EDL condition and sulfonates under the 1018 EAL condition. 45 These data indicate the importance of S-cycling under the EAL condition and the EDL is 46 associated to increased biocorrosion via indirect extracellular electron transfer mediated by 47 endogenously produced flavin-like molecules. 48 58 deliverability. Adding to scale of the problem, MIC occurs under a wide variety of environmental 59 conditions, including marine, freshwater and terrestrial locations. 60 MIC can involve a variety of different microorganisms that include sulfate-reducing bacteria (SRB) and iron-reducing bacteria (IRB) (Little et al. 2007, Enning and Garrelfs 2014, 62 Bonifay et al. 2017). Together with SRBs and IRBs, microbial consortia are typically involved in two mechanisms of MIC: EET-MIC (extracellular electron transfer, Type I), cross membrane 64 electron transfer (indirect and/or direct) (Kato 2016 and references therein), and/or metabolite-65 MIC (Type II), biocorrosion caused by secreted metabolites (e.g., H + , organic acids, sulfides) as 66 opposed to chemical corrosion which can refer to direct metal-oxidant interactions (Li et al. 2018, 67 Kannan et al 2018). Both EET-MIC and M-MIC are electrochemical corrosion processes (Li et 68 al. 2018, Dinh et al. 2004), and different EET mechanisms can promote the transfer of electrons 69 to or from extracellular solid compounds (Gralnick and Newman 2007, Kato 2016). The process 70 of EET can be mediated directly with metal surfaces via cellular connections and/or conductive 71 extracellular structures (e.g., Gorby et al. 2006) or indirectly via diffusible redox molecules 72 (Watanabe et al. 2009). The goal of this study was to elucidate nutrient ratio impacts on potential 73 M-MIC and/or EET-MIC mechanisms during initial biofilm formation under continuous growth 74 conditions in a defined growth medium. 75Extracellular electron transfer, which is shown to enhance MIC, is now recognized as a 76 more widespread microbial phenotype and suggests that EET-MIC could be a major mechanism 77 for biocorrosion world-wide (Nealson and Saffarini, 1994, Kato 2016, Huang et al. 2018.78 Previous work postulated that some SRBs contribute to MIC under various growth conditions 79 through Fe 0 oxidation via inte...

The ability to observe cells in live organisms is essential for understanding their function in complex in vivo milieus. A major challenge today has been the limited ability to perform higher multiplexing beyond four to six colors to define cell subtypes in vivo. Here, a click chemistry-based strategy is presented for higher multiplexed in vivo imaging in mouse models. The method uses a scission-accelerated fluorophore exchange (SAFE), which exploits a highly efficient bioorthogonal mechanism to completely remove fluorescent signal from antibody-labeled cells in vivo. It is shown that the SAFE-intravital microscopy imaging method allows 1) in vivo staining of specific cell types in dorsal and cranial window chambers of mice, 2) complete un-staining in minutes, 3) in vivo click chemistries at lower (μm) and thus non-toxic concentrations, and 4) the ability to perform in vivo cyclic imaging. The potential utility of the method is demonstrated by 12 color imaging of immune cells in live mice.